Abstract

Maturation and spawning of the penaeid prawn, Metapenaeus monoceros
from Cochin area have been studied. Five maturity stages, namdy, immature, early
maturing, late maturing, mature and spent-recovering, are recognised in the
development of the ovary. The maturation process of the intra-ovarian eggs is
described in detail. The minimum Size at first sexual maturity is found to be 118
mm. Metapenaeus monoceros breeds throughout the year with intensive spawning
during October to April. The nature and distribution of ova in the mature stage
indicate that the spawning of individuals of the species is restricted to a short
and definite period and the occurrence of mature females in various size groups
suggests that the species spawns more than once during its life-time. The fecundity
of the species has been estimated to be varying between 155,000 at 146 mm and
338,000 at 175 mm. The relationship between the length of the prawn and
fecundity is found to be logarithmic.